10 Best Kids Thermal Underwear Sets in The UK

Last updated on 24/08/2025

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LAPASA Boy's Thermal Underwear Set, Fleece Lined Kids Base Layer Long Sleeve Soft Top & Bottom (Thermoflux B03) Black 9-10 Years

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Why We Love It

Warmth like a mother's hug.
Flexibility for active movement.
Perfect for cold weather activities.

Main Highlights

WARM & COSY: LAPASA boy's thermal base layer is made with the finest fabric to give warmth, which gently wraps the child's tender skin like a mother's hug.
FLEXES & STRETCHES: This kid's thermal underwear set is designed to give flexibility by hugging the body and stretching with any movements, they will retain warmth without sacrificing range of motion or comfort.
BASE LAYER: Made of polyester and spandex blend, this kid's thermal underwear with natural colors is soft and light for layering under other clothes.
SNUG: Snug fit ensures no bunching around the waistline or sleeves and reduces heat loss.
COMFORT COOL AND COLD SEASONS: This kid's long sleeve base layer top and bottoms will sweat away to keep the child's body dry and comfortable. This thermal underwear is also great for skiing, running, cycling, and other activities, or as loungewear, a base layer in winter.

PowerLayer Skins for Boys Kids Base Layer Thermal Long Sleeve Top & Tights Football Compression Set - Navy Top + Navy Tights, 12-14 Years

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Why We Love It

Technical Compression for Kids.
Moisture-Wicking Technology.
Professional-Grade Quality.

Main Highlights

Top and Tights Set – Stay dry. Stay light. Stay powerful. Our technical compression base layer set for kids is made from premium materials, perfect for running, training, football, rugby, and other outdoor sports. Built to enhance performance in every activity.
Warmth and Flexibility - Our boys' thermal underwear set offers unmatched warmth and flexibility. The 4-way stretch fabric ensures you stay comfortable and unrestricted during football, cycling, running, hocky or any activity!
All-Weather Comfort - Engineered for all-weather comfort, our boys thermal set offers a lightweight thermal fabric that keeps you warm and dry during any sport or game.
Stay Cool and Dry – TCA’s moisture-wicking D.R.Y. technology keeps sweat at bay, so you stay dry and comfortable even during your activity. These kids thermals is ideal for high-performance training or everyday activities.
Athlete-Approved Excellence – At TCA, we design our sportswear with input from top athletes and coaches, ensuring performance and durability. From daily workouts to everyday wear, our activewear supports you through it all. Push your limits with TCA, built for athletes, made for everyone.

BUYKUD Kids' Boys Long Sleeve Base Layer Compression Underwear Athletic Shirt Tights Top & Bottom Set, Black, Label Size: 30

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Why We Love It

Highly durable and smooth.
Optimizes body temperature control.
Improves mobility and muscle support.

Main Highlights

92%Polyester,8%spandex
Abrasion-resistant, extremely smooth, highly elastic fabric that provides heat regulation, moisture wicking, and promotes sweat evaporation helps to prevent body odor
Highly elastic fabric allows enhanced mobility in any direction,perfectly for showing your muscle and good figure
Help compressing the core muscle area, quickly achieve the desired athletics effect，protect knee ligaments and promote skeletal muscle growth
Great for weight training, football, rugby, skiing, snowboarding Tennis Rowing Cycling Equestrian athletics etc

Base Layer Kids - Athletic Breathable Kids Thermals with Reflective Strips Long Sleeve Compression Base Layer Set, Fleece Lined Football Skins for Football Hockey Sports, Black 30

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Why We Love It

Keeps kids warm and cozy.
Wicks moisture for all-day comfort.
Ensures safety in low light.

Main Highlights

FLEECE-LINED TO KEEP WARM: Featuring a soft brushed back fleece lining that locks in heat for ultimate comfort. This skins for boys girls is perfect for layering under kids winter clothes or worn as standalone kids long johns.
MOISTURE-WICKING FABRIC: Design with breathable mesh on both sides of the armpits of the clothes provides stronger breathability and sweat wicking. This kids thermal base layer set pulls sweat away from the skin and quick drying to keep your kids dry and comfortable all day.
SAFETY REFLECTIVE DESIGN: Startseite kids base layer is designed with reflective strips at the thermal tops and leggings, allowing you kids to activity safely in low light conditions.
4 WAY STRETCH: Boys Girls thermals is made of 4-way stretch fabric, allow greater mobility in any direction. Flatlock seam helps to prevent chafing. High elastic wider waistband keeps the pant in place, but without any uncomfortable issue.
VERSATILE WINTER ESSENTIAL: Skins compression fit support and wrap athletic muscle groups, reduce the build-up of lactic acid, reducing the risk of injury and aiding blood circulation. This set is ideal for cold-weather activities like skiing, football, and daily life.

Roadbox Kids Thermal Underwear Set - Boys Fleece Lined Long Johns Soft Base Layer Compression Tops & Bottom Set for Skiing Black, Gray

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Why We Love It

Reliable Winter Warmth.
Breathable and Moisture-Wicking.
Stretchy and Flexible.

Main Highlights

Reliable Winter Warmth: This youth thermal set is crafted from 95% polyester and 5% spandex, with a fleece lining that captures body heat and blocks cold air. Lightweight yet warm, it offers effective insulation for winter days
Breathable and Moisture-Wicking: Designed to keep your child dry, this thermal set wicks moisture away and evaporates sweat quickly, preventing chills caused by perspiration and ensuring comfort during active play
Stretchy and Flexible: Made with highly elastic fabric, the thermal underwear adapts to the body’s shape for a snug, comfortable fit, perfect for growing kids. It retains its shape and stretch, even after repeated use
Skin Friendly: This garment has the advantage of being skin-friendly, providing children with a warm and cosy feel that will not wear out their tender skin, giving them a comfortable and warm dressing experience
Occasion: Whether skiing, playing football, hockey, or hiking, this thermal set keeps your child warm and comfortable during winter adventures. It’s a perfect gift for any active child, grandchild, or nephew

SIMIYA Kids Thermal Base Layer Set - Boys Youth Athletic Base Layer Set Compression Underwear Long Johns Bottom and Long Sleeve Top for Gym Sport Football Ski Green

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Why We Love It

Warm and comfortable materials.
Breathable and moisture-wicking.
Four-way stretch fabric.

Main Highlights

Cozy Warm Materials: The children's thermal underwear set is crafted from a blend of polyester and spandex, which ensure comfort, warmth, elasticity, and moisture protection. Skin-friendly and non-irritating, with no itchy tag, this boy’s thermal underwear set will become kid’s favorite go-to base layer on those bone-biting chilly days.
Sweat-Wicking Comfort: Keep kids dry and comfortable with breathable and moisture-wicking properties that quickly absorbs sweat. Our boys thermal underwear features breathable mesh under the arms helps evaporate moisture fast, so they stay warm without overheating, even during intense play.
Freedom to Move: With four-way stretch fabric, kids thermal base layer set allows kids to move freely without feeling restricted. The smooth seams and flatlock stitching prevents chaffing and discomfort while wearing. Whether it’s playing in the snow, skiing, or just running around, this set offers the flexibility they need for all their adventures.
Snug Fit Desigh: Crafted with a clean four-needle, six-thread technique and a form-fitting cut, boys thermal bottom underwear contours to your child’s body without being tight. The sleek, contrasting decorative lines add a touch of style, making it both functional and fashionable.
Versatile Winter Essential: Built to last, with no fading, pilling, or shrinking, this boys compression thermal set is perfect as a warm kids thermal underwear set for outdoor adventures or as cozy pajamas for cold winter nights, ensuring kids keep warm and happy, day or night!

orbiz Kids Thermal Base Layer Set Winter Warm Underwear Full Set Long John Bottom and Long Sleeve Top (White, 7-8 Years)

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Why We Love It

Luxurious look, trendy colors.
Perfect gift for kids.
Comfortable for all seasons.

Main Highlights

COMFORTABLE FABRIC: Utilising a special blend of Long-sleeve crew-neck kids thermal base layer one set with reinforced fabric made from 50% Cotton and 50% polyester keeps the body warm and moisture-wicking that's why used as a Kids Base Layer Thermal Shirt Long Underwear Set in Black and Charcoal.
KIDS THERMAL UNDERWEAR SET FOR ALL SEASONS: Our thermal underwear for kids is extremely comfortable for layering to give the ultimate warmth during the cold weather and it is Good for Spring, Summer, Autumn, and Winter. It features a crew neck, full-length pants, and long sleeves for extra coverage. Choose your favorite color and size as per the size chart.
SIMPLE AND LUXURIOUS PAJAMAS: Pull On closure. The design is Ideal for those seeking a luxurious look in kids' clothes. Designers choose the best trendy colors on reflection. 4-Way Stretch Fabric supports unrestricted movement. The underwear set contains 1 Top and 1 bottom. It is suitable as a baselayer when an extra layer is needed
PERFECT AS GIFT: Kids thermal leggings and Kids thermal vest is a great choice for babies, infants, toddlers,s or little kids as a Birthday, Kid's Day, Halloween, Valentine's Day, Anniversary, or Christmas gift. Our cotton blend thermal underwear kids set functions as a lightweight base layer to keep you warm.
SNUG FIT FOR ALL DAY: Long Sleeve Base Layer Top and Leggings Kids Thermals Set for Boys and Girls, Perfect for Daily Wear, Outdoor Sports or Games Like Football, Basketball, Soccer, Ice Hockey, Running, Skiing, Snowboarding and Baseball, and black long sleeve top kids are best boys thermal leggings.
WASHING AND CARE: Wash separately before wearing the kids' base layer. Use mild detergent only. Don't bleach! Line Dry! We try to give babies the perfect experience every day..

Kids Thermal Underwear Skins Set Long Sleeve Top Vest and Long Johns Leggings, Boys Girls Base Layer, Football, Sports, Ski Black

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Why We Love It

Keeps kids warm and comfortable.
Quickly wicks away moisture.
Soft and cozy microfiber fleece.

Main Highlights

Children's Extreme Ultralight Warmest Top and Tights Sets make all favorite cold weather activities more pleasant. Whether snowboarding; skiing; camping or other outdoor sports; traveling and even sleeping Outland Thermal set keeps your kids comfortable.
The Thin Lightweight Thermal Clothing maintains body heat at a cool temperature by wicking moisture away from the skin; drying quickly and insulating from the cold.
The Basic Boy and Girl Underwear Undershirt and Bottom Leggings have an interior microfiber fleece that is soft and cozy; feels great against your skin and under a layer of clothing
We have your size! For babies, toddlers, youth; juniors; teens; boys, and girls from 2-4 to 14-16. Several solid color options, including a tactical camo shirt and our new HEATHER GREY.
Does not restrict movement; feels like a second skin with four-way stretch and gives your kids the needed warmth without thick or heavy layers. The suit Kids Underwear long johns can be repeatedly washed without shrinking. Machine wash dries quickly.

Hikewin Girls Thermal Underwear Set for Kids Long Johns Underwear Ultra Soft Winter Base Layer for Girls Pink 12-24Months

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Why We Love It

Kids stay warm and dry.
Ultra soft for maximum comfort.
Perfect underlayer for cold weather.

Main Highlights

High quality fabric: a new functional fabric, called diamond velvet.very fluffy, and the erect fluff increases the amount of static air, which is very warm.particularly soft and breathable, Skin friendly and warm fabric makes this thermal top a must-have item in your baby wardrobe.
Heat Retention: Kids thermal underwear set will keep your child warm. It's great as a baselayer under their clothes or to wear alone around the house.
Ultra Soft: high-quality plush blend, kids long underwear will keep your kids comfortable when they’re out in the cold or relaxing at home.
Moisture Wicking: Help your kids stay dry and odor free with a set of thermal underwear for kids. They wick away moisture during every activity without discomfort.
Layer Up: Long johns for kids are perfect as a base layer. They have no added bulk so they fit under your boy’s regular clothes easily for added protection from the cold.

Dtone Kids Athletic Base Layer Set Boys Thermal Long Sleeve Top and Leggings for Football Sport Ski Black 8-9 Years

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Why We Love It

Exceptional comfort for active kids.
Moisture-wicking keeps kids dry.
Durable quality for lasting wear.

Main Highlights

Exceptional Comfort for Little Explorers: Our kids base layer is crafted with ultra-soft fabric, ensuring a gentle touch against your child's skin for all-day comfort. The boys thermal base layer set offer a snug yet flexible fit, allowing for unrestricted movement. Whether under sports gear or winter attire, this base layer ensures your child can run, jump, and play without any hindrance. It's the perfect choice for active kids who need comfort and freedom to explore.
Superior Moisture Management for Active Days: Equipped with advanced moisture-wicking technology, our kids football skins efficiently absorb and rapidly dry sweat. This keeps your child dry and comfortable during rigorous activities like hockey, football, or running in cold weather. The fabric also helps eliminate odors, ensuring freshness and hygiene throughout the day. Your child can stay active and odor-free, making these long johns an ideal choice for any cold-weather activity.
Unsurpassed Warmth for Chilly Adventures: The stretchy brushed interior of our boys football underlayer provides exceptional warmth, perfect for cold winter nights as ultra-soft pajamas or for outdoor adventures in chilly conditions. It offers outstanding heat retention, ensuring your child stays comfortably warm without overheating, whether indoors or during moderate outdoor temperatures. This base layer is a cozy shield against the cold, keeping your child warm and comfortable.
Durable Quality for Long-Lasting Use: Made from high-quality materials, our boys thermal base layer are built to last. They withstand frequent washing without losing shape, color, or functionality. Parents consistently report that these sets remain in excellent condition after numerous washes, offering great value for money. Your investment in comfort and warmth will last through many seasons, making these sets a reliable choice for your child's wardrobe.
Versatile Functionality for Every Occasion: Our kids thermal base layer is incredibly versatile. It can be worn as long johns kids for added warmth during winter sports like ice hockey, football, and skiing, providing essential insulation. It also serves as comfortable pajamas for cold nights or casual wear at home, making it a practical choice for toddlers and older children alike.

8.7

Excellent

We scanned 1367 products

We reviewed these offers relevant to the Kids Thermal Underwear Sets within online retailers such as Amazon, eBay and other local retailers, ensuring we covered all major brands and models. The products we selected come from trusted brands like LAPASA, PowerLayer, BUYKUD, Startseite, Roadbox, SIMIYA, orbiz, Ultra Dry, Hikewin, Dtone, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Kids Thermal Underwear Sets in the market, we considered we took a deep dive into 6836 online reviews , focusing on elements like user satisfaction, performance in real-world conditions, and long-term reliability. Our ranking also evaluates each review’s relevancy, authenticity, up-to-dateness and depth so that the comparison is more sound.

We concluded that:

The clear winner of our analysis is LAPASA Boy's Thermal Underwear Set, Fleece Lined Kids Base Layer Long Sleeve Soft Top & Bottom (Thermoflux B03) Black 9-10 Years. We love many things about this product by LAPASA. What sets it apart from the competition is Warmth like a mother's hug. , Flexibility for active movement. , Perfect for cold weather activities. .
The best value product for most shoppers and where user satisfaction is continuously the highest is PowerLayer Skins for Boys Kids Base Layer Thermal Long Sleeve Top & Tights Football Compression Set - Navy Top + Navy Tights, 12-14 Years by PowerLayer based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Kids Thermal Underwear Sets and the best cost-to-value ratio is Dtone Kids Athletic Base Layer Set Boys Thermal Long Sleeve Top and Leggings for Football Sport Ski Black 8-9 Yearsat Dtone with a % discount.
Our list of the best Kids Thermal Underwear Sets is updated regularly to reflect new releases and changes in product availability, so be sure to check back often for the latest rankings and discounts.

10 Best Kids Thermal Underwear Sets in The UK

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We scanned 1367 products

We concluded that: